LAX shooting prompts renewed focus on AR-15 class rifles

A movie theater in Aurora, Colo., an elementary school in Newtown, Conn. and now Los Angeles International Airport – they all have one thing in common: the choice of gun used to terrorize an unsuspecting public.

Friday's shooting at LAX left one Transportation Security Administration (TSA) employee dead, two more injured and an unknown number of witnesses harmed. It started around 9:20 a.m. PT when the gunman, later identified as 23-year-old Paul Ciancia, reportedly walked to the security checkpoint in LAX's Terminal 3, pulled a rifle out of a bag and started firing. A chaotic scene ensued as Ciancia allegedly made his way through the security area and into the terminal, where he exchanged gunfire with police before being apprehended.

Witnesses uploaded photos of the scene to Twitter. One of the images, posted by Tom Donnelly, shows a rifle on the ground in the terminal.

Immediately speculation ramped up that it was an AR-15, the same kind of gun James Holmes allegedly used to kill 12 people in Aurora, the same gun Adam Lanza used to kill 26 at Sandy Hook Elementary.      Since then, the rifle has become the target of gun-control advocates, who question the need for a semi-automatic weapon. In the immediate aftermath of the Washington D.C. Navy Yard shooting in September, early reports jumped on the AR-15 as the weapon used in that incident that resulted in the death of 12 people; those reports were later proven false as Aaron Alexis first used a shotgun, then a pistol, according to reports.

Ciancia used an AR-15, which ABC News Los Angeles reported Friday afternoon. And with this news, proponents of gun-control will feel even more emboldened, as the likes of Piers Morgan displayed on Friday.

The debate will begin again: Is it the person or the gun laws? But that's a question for another day. For now, the question is: Why the AR-15?

Designed in the early 1950s, the gun retails for around $1,000 and remains popular because people "like the design of the rifle because it is a very accurate rifle," according to Casey Torres, an expert from Kerley's Hunting and Outfitting in Cupertino, Calif. Torres added that it's lightweight and has an ergonomic design.

A representative from Elite Armory, a gun store in Castro Valley, Calif., told Yahoo News that the gun is "popular throughout the U.S. and California." According to the Bureau of Alcohol, Tobacco, Firearms and Explosives, more than two million AR-15-type rifles were sold between 2000 and 2010.

To purchase the gun in California, you must show proof of residency, such as a utility bill or car registration with the same address as your driver's license, according to Torres. The information is then run through the state computer, and if it the purchaser passes the background check, he or she can acquire the firearm after a 10-day waiting period.

According to Torres, the background check looks for things like "violent misdemeanors, domestic violence. It will also look for any violence in your past, if you were institutionalized, a 72-hour psych hold, you are disqualified from purchasing a firearm. Or if you have a felony." That's to pass the background check for the state of California. There is also a background check from the federal government.

How Ciancia, who is reportedly from New Jersey but was living in California, came in possession of the rifle is not yet known.